This invention relates to helmet mountable displays and, more particularly, to a self-contained, full-color, stereoscopic high-resolution helmet mountable video display, such as may be used in simulation systems like trainers, or during actual vehicle or aircraft operation as a display for sensors and/or instruments.
One type of helmet mountable display (HMD) system using a four lens optical system, a folding mirror and horizontal and vertical scanning mirror is described and claimed in U.S. Pat. No. 4,897,715, issued Jan. 30, 1990, assigned to the assignee of the present invention and incorporated in its entirely herein by reference thereto. Another form of HMD system uses two lenses in its optical system; this system, also invented by the present inventor, is described and claimed in U.S. Pat. application Ser. No. 07/456,502, filed Dec. 27, 1989, also assigned to the present assignee hereof and also incorporated herein in its entirely by reference. Although the inventions as described and claimed in U.S. Pat. No. 4,897,715 and in Pat. application No. 07/456,502 offer substantial improvements over prior display systems, the use of two or four lenses, even if able to be fabricated from a light-weight refractive material such as plastic rather than glass, still represent a significant weight that must be carried and accounted for by the wearer of the helmet.
It is desirable to reduce further the weight of the HMD system as described and claimed in either of the aforementioned U.S. Pat. No. 4,897,715 or application No. 07/456,502, while still obtaining the benefits thereof; elimination of any components is also expected to result in a cost reduction.